Manually-operated handheld air displacement pipettes using interchangeable and disposable plastic tips have been available for more than forty years, and remain the dominant small-volume liquid handling tools in scientific and biomedical laboratories. They are generally lightweight, intuitive, simple to use, and reliable.
Although electronically operated handheld pipettes have been available for more than twenty-five years, they generally have not been as popular as manual pipettes. Electronic pipettes have not reached comparable levels of intuitive operation, ease of use, or ergonomics. Except in some specific applications, they are generally less favored for several reasons.
Electronic pipettes are generally larger and heavier than traditional manually operated pipettes. An electronic pipette needs space for a battery, a control circuit, and a drive motor in addition to the moving piston, which in a manual pipette is driven by a simple plunger button. Historically, electronic pipettes have been difficult to program and use, as low-power electronics and size and cost constraints have limited the user interface to a few buttons and a small, monochromatic, fixed-segment LCD display. And with immature battery technology, a relatively large and heavy battery needed to be used, and required fairly frequent recharging or replacement.
Because of their increased complexity, electronic pipettes are generally more expensive than their fully manual counterparts. They are less tactile to use, more complex, and as a consequence have greater potential unreliability.
On the other hand, electronic pipettes provide several key advantages over traditional manual pipettes: they offer multiple features and modes of operation that are either impossible or difficult to achieve with manual pipettes (such as multidispense modes, complex sequences of operations, and remote controlled operation). Because there is no springloaded plunger rod, the pipette is particularly ergonomic, with the user's hand subject to considerably reduced forces. And because of their electronic nature, electronic pipettes are capable of storing information about the pipetting operations that have been performed, are consistent from cycle to cycle, and are less reliant on user technique.
But in general, the advantages have not outweighed the disadvantages for many users. The ease of use of a manual pipette has been a difficult advantage for electronic pipettes to overcome.
Accordingly, there is a continuing need for an electronic pipette that is not only flexible and powerful, but is simple enough in operation to compete with traditional manually operated pipettes.